:)

Less fictional (only slightly less,) perhaps VO has reinvented N. Tesla’s transparent blimp material for a submarine hull, sheets of some sort of plasma-treated micro-laminate. If the lattice mismatch between thin layers puts the material under enormous internal stress, like super-hyper-mega-tempered glass, then dunking it in the depths off Guam is only a slight increase in pressure.

Ah, or Viktalen, the hull and windows of Nazi flying saucers. :) The formula provided by aliens/psychics, of course (or more likely stolen from Tesla, along with detailed electrodynamic hover-disk plans.) Oops, lots of others have already speculated much more wildly: http://en.wikipedia.org/wiki/List_of_fictional_super_metals

For one, the submarine looks too “designed” to be real – if you look at other super-deep-diving submarines, it’s obvious they’re designed purely for function.

I’m not really doubting them, it just seems so incredible. I guess I will believe it when I see it. I’ll bet the real thing won’t look very much like the artist renditions!

But the best part is:

“The submarine was originally commissioned by Sir Richard’s close friend and fellow adventurer Steve Fossett who had intended to complete the first solo dive to the depths of the Mariana Trench.”

Wasn’t that the dude got lost a few years back while atempting to round the world or so?

Whoooohoo! That sounds trustworthy!

So, obviously the best qualified person on the planet for doing this stunt. Amazing what a gigantic pile of cash can buy, isn’t it?

Virgin Galactic passengers = 0
Virgin Galactic deaths = 3

Just saying.

As with combat submarines, the outer shell is merely hydrodynamic. There is a pressure vessel within the outer shell: a cylinder with hemispherical endcaps. It looks like the pilot lays prone.

The pressures at these depths are INCREDIBLE. This has 2 main implications. First, any volume large enough to be occupied by humans must be spherical (for strength); I don’t know of any other shape that’s been tested successfully for that kind of pressure and has a hatch for people to get in and out. The fighter-jet-style canopy on this vehicle looks very suspect.

The second implication of pressure is that ballast tanks are impractical for deep diving vehicles (the energy required to force water out of tanks, called “blowing”, is prohibitive; nevermind the issues of creating deep-rated plumbing in the first place). Because of this, deep-rated vehicles are made to be neutrally buoyant, and change their depth by driving up or down in the water column.

At this point, you might be thinking “ok, this vehicle looks like it is doing exactly that — driving down to the bottom of the sea”. You’re right, but that’s impractical too. Deep-rated vehicles drive around once they’ve reached depth, but to get to the bottom and back is over 12 miles round trip — even further if you don’t go straight down and straight back up. That would require a HUGE bank of deep-rated batteries, which would be ridiculously heavy. Real deep-rated vehicles use 2 drop weights: 1 that’s jettisoned when they reach their target depth, and another that’s jettisoned when they come back up. Long story short (too late…) the promo video looks very suspect.

There are 2 deep-rated vehicles that might illustrate where I’m coming from: Nereus (an unmanned vehicle that holds the depth record), and Trieste (a bathyscape that carries people down to depth).

Nereus: http://www.whoi.edu/page.do?pid=10076

Trieste: https://secure.wikimedia.org/wikipedia/en/wiki/Bathyscaphe_Trieste

Both of these vehicles carry quite a lot of flotation to maintain neutral buoyancy despite their weight. For perspective, the little ball under Trieste is where the people sit, and all the rest is flotation.

I’d love to be wrong about this, but I’m not convinced that Richard Branson suddenly solved every difficult problem facing underwater vehicle designers for the past 50 years.

Hey, there’s a dsv in Seattle’s back yard. The Naval Undersea Museum over in Bremerton has Trieste II, also Deep Quest.

http://images.google.com/images?hl=en&source=hp&q=“naval+undersea+museum”+dsv